Navigation support

Abstract

The present invention relates to guidance during a medical intervention. In order to provide an improved navigation support with a facilitated setup, a system ( 10 ) for navigation support is provided. An image data input ( 12 ) receives a plurality of acquired 2D X-ray images of a subject's body from different angles. A set of markers, which are visible in X-ray images and which are detectable by a navigation system, is assigned to the subject. A marker detecting arrangement ( 16 ) is provided that detects a current spatial location of the markers assigned to the subject. A data processor ( 14 ) reconstructs a 3D volume of the subject based on the plurality of 2D X-ray images. At least a part of the markers is arranged outside the volume covered by the reconstructed 3D volume of the subject, while the markers are visible in the 2D X-ray images. The data processor ( 14 ) identifies the markers in the 2D X-ray images based on image data of the plurality of 2D X-ray images outside the 3D volume and determines a spatial location of the markers in relation to the 3D volume of the subject. The data processor ( 14 ) also registers the reconstructed 3D volume of the subject to a current spatial position of the subject based on the detected current spatial location of the markers and the determined spatial location of the markers in relation to the 3D volume of the subject. An output interface ( 18 ) provides the registered reconstructed 3D volume for navigation.

The invention claimed is: 
     
       1. A system for navigation support, the system comprising:
 a marker detecting arrangement configured to detect a current spatial location of a set of markers assigned to a subject; 
 a processor is configured to: 
 receive a plurality of 2D X-ray images of the subject from different angles, wherein the set of markers are visible in the X-ray images;
 reconstruct a 3D volume of the subject based on the plurality of 2D X-ray images; wherein at least a part of the set of markers is positioned outside volume covered by the reconstructed 3D volume of the subject; 
 identify at least the part of the set of markers in the plurality of 2D X-ray images based on image data of the plurality of 2D X-ray images outside the 3D volume and determine a spatial location of the set of markers in relation to the 3D volume of the subject; 
 register the reconstructed 3D volume of the subject to a current spatial position of the subject based on the current spatial location of the set of markers as detected by the marker detecting arrangement and the determined spatial location of the set of markers in relation to the 3D volume of the subject; and 
 
 provide the registered reconstructed 3D volume for navigation support. 
 
     
     
       2. The system according to  claim 1 , wherein for the determination of the spatial location of the set of markers in relation to the 3D volume of the subject, the processor is further configured to use 2D image data from the plurality of 2D X-ray images outside the 3D volume of the subject and to detect the set markers in the 2D image data. 
     
     
       3. The system according to  claim 1 , wherein for the determining of the spatial location of the set of markers in relation to the 3D volume of the subject, the processor is further configured to provide an extended field of view reconstruction including a visualization of high-contrast items or items for which a-priori knowledge is available regarding a shape or X-ray absorption properties, the items appearing in the 2D image data outside the 3D volume of the subject. 
     
     
       4. The system according to  claim 1 , wherein the marker detecting arrangement comprises a plurality of optical cameras configured to detect the markers. 
     
     
       5. The system according to  claim 1 , wherein the marker detecting arrangement comprises an electromagnetic tracking arrangement attached to a base, the electromagnetic tracking arrangement configured to detect the set of markers. 
     
     
       6. The system according to  claim 1 , wherein for the detection of the set of markers in the 2D image data from the plurality of 2D X-ray images outside the 3D volume of the subject, the processor is further configured to provide information about at least one of a shape of the set of markers and X-ray absorption properties of the set of markers and use the information for artifact correction before detection of the markers. 
     
     
       7. The system according to  claim 1 , further comprising:
 an X-ray imaging system configured to acquire 2D X-ray images from a plurality of angles for providing the plurality of acquired 2D X-ray images of the subject; and 
 wherein the processor is further configured to link a spatial coordinate system of the X-ray imaging system with a spatial coordinate system of the marker detecting arrangement. 
 
     
     
       8. The system according to  claim 7 , further comprising a plurality of at least two markers configured for temporal assignment to the subject. 
     
     
       9. The system according to  claim 7 , wherein the markers are configured to be assigned to the subject, which may be outside a region of interest, which region of interest is set to be covered by the reconstructed 3D volume. 
     
     
       10. A method for navigation support, the method comprising the following steps:
 acquiring a plurality of 2D X-ray images of a subject's body from different angles; wherein a set of markers, which are visible in X-ray images and which are detectable by a navigation system, is assigned to the subject; 
 reconstructing a 3D volume of the subject based on the plurality of 2D X-ray images; wherein at least a part of the set of markers is arranged outside the volume covered by the reconstructed 3D volume of the subject, while the markers are visible in the plurality of 2D X-ray images; 
 identifying the set of markers in the 2D X-ray images based on image data of the plurality of 2D X-ray images outside the 3D volume, and determining a spatial location of the set of markers in relation to the 3D volume of the subject; 
 detecting a current spatial location of the set of markers assigned to the subject; 
 registering the reconstructed 3D volume of the subject to a current spatial position of the subject based on the detected current spatial location of the set of markers and the determined spatial location of the set of markers in relation to the 3D volume of the subject; and 
 providing the registered reconstructed 3D volume for navigation support. 
 
     
     
       11. The method according to  claim 10 , wherein for the determining of the spatial location of the markers in relation to the 3D volume of the subject, 2D image data from the plurality of 2D X-ray images outside the 3D volume is used and the set of markers are detected in said 2D image data. 
     
     
       12. The method according to  claim 10 , wherein for the determining of the spatial location of the markers in relation to the 3D volume of the subject, an extended field of view reconstruction is provided including a visualization of high-contrast items or items for which a-priori knowledge is available regarding a shape or X-ray absorption properties, the items appearing in the 2D image data outside the 3D volume of the subject. 
     
     
       13. A non-transitory computer-readable storage medium having stored a computer program comprising instructions which, when executed by a processor, cause the processor to:
 acquire a plurality of 2D X-ray images of a subject's body from different angles, wherein a set of markers, which are visible in X-ray images and which are detectable by a navigation system, is assigned to the subject; 
 reconstruct a 3D volume of the subject based on the plurality of 2D X-ray images, wherein at least a part of the set of markers is arranged outside the volume covered by the reconstructed 3D volume of the subject, while the markers are visible in the plurality of 2D X-ray images; 
 identify the set of markers in the 2D X-ray images based on image data of the plurality of 2D X-ray images outside the 3D volume, and determining a spatial location of the set of markers in relation to the 3D volume of the subject; 
 detect a current spatial location of the set of markers assigned to the subject; 
 register the reconstructed 3D volume of the subject to a current spatial position of the subject based on the detected current spatial location of the set of markers and the determined spatial location of the set of markers in relation to the 3D volume of the subject; and 
 provide the registered reconstructed 3D volume for navigation support.